COVID-19 Drug Development: Role of Drug Repurposing

*Kenneth Bitrus David, Yusuff Azeez Olanrewaju and Cynthia Chidera Okafor*

### **Abstract**

The COVID-19 pandemic came at a time when the scientific world was least prepared for it. It emerged at a time when there were variable research availability and limited mechanistic insights about the virus. Amid these challenges, research works were carried out in a bid to discover ways of curbing the spread of the virus and improving the health outcome of the population. Drug repurposing was one concept that was explored by scientists. Through this concept, already existing drugs were repurposed for the treatment of COVID-19, with incredible results seen. This chapter provides insights on some repurposed drugs, steps taken in drug repurposing, challenges peculiar to the methods, and a framework for continuity.

**Keywords:** drug repurposing, COVID-19, drug development, pandemic

### **1. Introduction**

Coronaviruses, a large group of positive-sense RNA, single-stranded, and enveloped viruses have been one of the viral sources of respiratory diseases [1]. In December 2019, they caught the attention of the world when a strain of the virusn-CoV-19, which was later renamed SARS-CoV-2 virus-caused epidemic cases of respiratory tract infection in Wuhan, China. The initial cases were presumed to be complications of pneumonia and were treated as such, until when further studies were conducted as regards the rate of spread, morbidity, and mortality of the disease [2]. Findings from studies conducted provided evidence that made the World Health Organization (WHO) declare the disease as a global health emergency and subsequently a pandemic.

For the first 12 months since the inception of the pandemic, COVID-19 spread worldwide, gravely affecting countries such as Turkey, Iran, Poland, Mexico, Germany, Colombia, Argentina, Spain, Italy, United Kingdom, France, Russian Federation, Brazil, India, and the USA, with each country recording over 1 million confirmed cases (https://covid19.who.int/accessed on August 25, 2022). The lack of proper treatment and vaccine made the mortality rate quite high [3].

Some of the measures used in curbing the spread of the virus and improving the quality of life of those infected included national and international lockdown, travel restrictions, mandatory use of face covering, washing of hands, and social

**Figure 1.**

*Showing the timeline of the COVID-19 pandemic and details of repurposed drugs used [5–9].*

distancing [4]. Also, some drugs were repurposed for the management of the disease, and vaccines were developed. **Figure 1** shows the timeline of the COVID-19 pandemic and details of some repurposed drugs used [5].
